Shear developer



Dec. 5, 194.4. J. F. SEILER 2,364,481

SHEAR DEVELOPER Filed Dec. 7, 1945 2 Sheets-Sheet l Patented Dec. 5,1944 SHEAR DEVELOPER James F. Seilcr, Washington, D. 0., assignor toAmerican Wood-Prescrvers Association, a corporation of IllinoisApplication December 7, 1943.

14 Claims.

The invention relates to an improvement in apparatus adapted for makingthe construction of my Patent 2,022,693, issued December 3, 1935. Inthat patent is described a structure made up of wood and concrete inwhich are employed shear developers adapted to partiallyreceive anddistribute the loads carried by the structure. It is a purpose of thepresent invention to provide an improved form of shear developer. Sincethese devices are disposed as connecting units between the concrete andwood, it is essential that they engage both and form a satisfactoryconnection. This requires the developers to be secured into the wood insuch a Way as to have sure strong seats .and extend out sufficiently tobe securely embedded in the concrete when it is applied. 1 It has beenfound that this may be done most effectively by employing a speciallyshaped shear developer as set out herein...

The shear developers in general are set in or across a trough made bythree pieces ofwood, the middle one being set below or inwardly of theedges of the adjacent members. In order to sheet a strong-setting, theshear developer must engage the piece of wood at the bottom of thetrough and also at its sides must engage the extending edges of the woodat the side of the trough. It has been found that this may be doneefliciently by employing a shear developer especially adapted to thisend and also so as to cross and close almost the entir area of thetrough and at the same time extend therebeyond and be free to be engagedby the concrete when put in place.

In order to insure better holding in the wood, the shear developers maybe provided with irregularities or projections at some or all of theareas which are buried in the Wood.

In order to make the shear developer better resist the stresses in thecompleted structure, it may be dished or bent or deformed especially atthe areas engaged by the concrete and more especially about the holes ifpresent.

An additional purpose of the present invention is to provide means forconveniently handling the shear developers during manufacture, trans:portation and installation. This may conveniently consist of a holeformed at a predetermined part in the shear developer so as to act as anindex or guide to the proper placing of it in the wooden base. The holemay also furnish a seat for a bolt or spike passing therethrough andentering the wood and being buried in the concrete to further reinforcethe shear developer against movement during pouring of the concrete andconstruction activities and also in the com- Serial No. 513,292

pleted structure which may thus be made more sturdy.

An improved tool for grooving the seats for the shear developers is alsoincluded.

This application is a continuation-in-part of my application Serial No.351,007, filed August 3, 1940.

In the accompanying drawings, Figure 1 is a front elevation of one formof shear developer in place in a trough between pieces of wood which areshown in section. Fig. 2 is a fragmentary plan view of a portion of ablank from which may be made a plurality of shear developers. Fig. 3 isa front elevation of a tool which may be conveniently used to form seatsfor shear developers in the Wood which is shown in section. Fig. 4 is afragmentary vertica1 section on the line ll of Fig. 3. Fig. 5 is a viewsimilar to Fig. 1 showing another form of shear developer. Fig. 6 is avertical sectionon line 5-6 of Fig. 5 showing a spike in place, and Fig.'7 is a section on the line 'L-T of Fig. 5.

The trough into which the shear developers are set is normally about aswide as it is deep and it is desirable that the developer have a sturdysure engagement with the bottom and with both sides of the trough. Oneelement which may determine the strength of engagement may be how deepinto the Wood the developer enters. It has been found that a pointed endmust go much further into the wood to obtain a comparable seating thanif the end is obtuse or wider. It has also been found that an inclinedseat is more easily made in the sides of the trough with such an end.The shear developer H) is made triangular in shape but With one pointomitted forming a straight edge at H. Preferably the shape will be thatof a trapezoid in the form of a truncated isosceles triangle, the apexbeing cut off parallel to the base. This truncated end is embedded asuitable depth in the wood H at the bottom of the trough giving a widegrasp on the wood. By being embedded to a slight depth it may extendnearly entirely across the bottom of the trough. In this position thesides of the shear developer will be embedded through most of theremainder of their extent in the Wooden side walls E5 of the trough asindicated at l3. This may give a strong engagement with the wood to holdthe shear developer more or less certainly in place and so allow it toform a more or less sturdy connection with the concrete to be put inplace. The base M of the triangle and a small area adjacent theretoextend beyond the edges of the side walls 15 of the trough and are freeto be embedded in concrete to be applied. The concrete also enters thetrough and makes contact with the entire surface of the shear developersI ex cept the portions buried in the walls l5 and the bottom 82 of thetrough.

The shear developer near its base is provided with a hole [6 which mayact as a key and aid in holding the concrete. It will be noted that theform of shear developer shown leaves, when installed, small triangularareas IT at the bottom corners of the'trough unfilled and concretesettling intothese to some extent may act as keys and assist in holdingthe concrete and to preserve the continuity of concrete on both sides ofthe shear developer.

Because of their peculiar shape the shear developers l0 may beeconomically made by cutting or stamping or the like from a strip orsheet of suitable thickness without substantial loss of material bybeing formed and separated as shown in Fig, 2 where the edge of eachshear developer fully adjoins the edge of an adjacent shear developer.

Large numbers of shear developers are used in each structure and thehole I6 is found a convenient means of fastening them together forshipping and handling during manufacture, transportation, storage andinstallation. Unskilled labor may be used for installation since thehole I 6 may be used as a guide or index as it may indicate the edge ofthe device which extends from the trough and is to be entirely coveredwith concrete.

As shown in Fig. 6, a spike or nail 35 may be passed through the holeand driven into the bottom wood member l2. This tends to hold the sheardeveloper rigidly in place and at the same time the spike may furnishadditional anchorage for the concrete.

The shear developer may be made of suitable material to stand thestrains to which it is put, being preferably of structural grade steel.It may be desirable to have the shear developer plated or coated such asby galvanizing or dipping in zinc or other protective coverings. Forsuch procedure the hole l6 forms an easy and convenient means forhandling during coating.

To further reinforce or strengthen the shear developer, it may bedeformed or dished as shown at 36 in Figs. 5, 6 and 2. dished portionare present, desirable to have the hole of the shear developer.

The shear developer may be installed by being it may or may not be IS inthe dished part suitably positioned and driven in place and, to

aid in such procedure, the sides and truncated end may be sharpened ifdesired. It is found better and more convenient in general, however, toemploy a tool for cutting or grooving the seats into which the sheardevelopers are to be placed. Such a tool is illustrated in Figs. 3 and4. There is provided a blade corresponding in size and shape to theshear developer to be installed. This blade may .be made of hardenedcutting metal and is sharpened at its edges 19 and at its truncated end20 and is held in a slot 2| in a handle 22, the end 33 of which may beso shaped that it may be driven by a manual sledge hammer or in astandard pneumatic hammer or other power-operated device. The handlealso carries guides 23, one on each side of the blade I8. Each guide hasa tongue 24 slightly narrower than the width of the trough between themembers I5 but somewhat longer than. the depth of the trough. At itsupper end each tongue 24 is provided with When both hole and laterallyextending projections 25 to provide for proper connection to the handleand to brace the device. When the tongue 24 reaches the bottom member l2a sufllcient groove has been made to receive the shear developer. Thebottom of the handle 22 finds a seat 26 in the guides 23. Bolts 21 holdthe guides 23 onto the handle 22 and pass through enlarged holes 28 inthe blade l8. A bolt 29 is shown holding the guides 23 against the bladeis and passing through an enlarged hole 30 in the blade. Thus pressurefrom the handle 22 is put on the blade l8 at its upper edge in the slot2| and no strain is carried by the bolts 21 and 29 to the blade [8. Whendesired, the bolts 21 and 29 may be removed and guides and blades ofother sizes and shapes may be substituted to correspond with whatevershear developers are being installed in whatever troughs are being used.

To aid in holding the shear developer in place in its seat, cuts 31 maybe provided at points in their margins or edges l3 which are adapted tobe set in the wood. The portions 38 below the cuts may be pushed orturned out of the plane of the shear developer. As indicated especiallyin Fig. 7, such cut and turned or pushed out portions may pass throughthe wood resiliently and finally seat themselves in such a way as topress into the wood and grip it so as to better resist the strains andhold against withdrawal or displacement. While not essential it may bedesirable that the cut portions be not pushed out farther than thethickness of the material as shown.

The shear developers may be plain as shown in Fig. 1, or may have holes,dished portions and gripping portions turned out at cuts in their edgesas illustrated in Figs. 5 and 7, or any one or more of these extraelements may be omitted.

Since the dished portion 36 extends 0n the same 'side of the sheardeveloper as the turned out portions 38, even the shear developer withall the details shown in Fig. 5 may be made by a single operation of thedie from the strip of metal, as indicated in Fig. 2.

Forms and dimensions may be varied to meet desires and conditions of usewithout departing from the invention.

I claim:

1. A shear developer comprising a truncated isosceles triangular metalplate with a perforation near the base and substantially equidistantfrom the sides.

2. A shear developer for wood and concrete structure comprising atruncated isosceles triangular metal plate adapted to have an area nearits base extending into the concrete and its truncated end and most ofits sides embedded in the wood.

3. A shear developer for a wood and concrete structure comprising atruncated isosceles triangular metal plate adapted to be seated in atrough in the wood with its truncated end embedded in the bottom of thetrough and most 'of its sides embedded in the sides of the trough andthe remainder embedded in the concrete with a portion adjacent the baseextending beyond the mouth of the trough and provided with a hole in theextending portion.

4. A shear developer seat grooving tool comprising a blade correspondingin size to the shear developer and sharpened at its edges, a pair ofguides one on each side of the blade, a tongue on each guide fitting inthe trough into. which the shear developer is to be seated and engagingthe material at the bottom of the trough and limiting the entrance ofthe blade, and a handle carrying the blade and the guides and adaptedwhen hit to cause the blade to groove the seat for the developer.

5. In a device of the class described, a trun- ,cated isoscelestriangular metal plate adapted to be seated in a trough of wood with itstruncated end and part of its sides embedded in the bottom of the troughand most of the rest of its sides embedded in the sides of the trough.

6. A shear developer comprising a truncated isosceles triangular metalplate with a reinforcing depression near the base and between the sides.

7. A shear developer comprising a truncated isosceles triangular metalplate with a perforation near the base and substantially equidistantfrom the sides, a reinforcing depression, and portions at the marginscut and pushed out.

8. A shear developer for a wood and concrete structure comprising atruncated isosceles triangular metal plate adapted to be seated in atrough in the wood with its truncated end embedded in the bottom of thetrough and most of its sides embedded in the sides of the trough and theremainder embedded in the concrete with a portion adjacent the baseextending beyond the mouth of the trough and portions at wood-embeddedpoints out and pushed out to engage the wood, and a reinforcingdepression in the concrete embedded portion.

9. A shear developer for a wood and concrete structure comprising a'truncated isosceles triam gular metal plate adapted to be seated in atrough in the wood with its truncated end embedded in the bottom of thetrough and most of its sides embedded in the sides of the trough and theremainder embedded in the concrete with a portion adjacent the baseextending beyond the mouth of the trough and portions at wood-embeddedpoints cut and pushed out to engage the wood.

10. A shear developer for wood and concrete structures comprising atruncated isosceles triangular metal plate adapted to have an area nearits base extending into the concrete and its truncated end and most ofits sides embedded in the wood, portions at embedded points cut andpushed out to en age the wood. 1

11. A shear developer for wood and concrete structures comprising atruncated isosceles triangular metal plate adapted to have an area nearits base extending into the concrete and provided with a reinforcingdepression and its truncated end and most of its sides embedded in thewood and portions at embedded points pushed out to engage the wood.

12. A shear developer for wood and concrete structures comprising atruncated isosceles triangular metal plate adapted to have an area nearits base provided with a hole and extending into the concrete and itstruncated end and most of its sides embedded in the wood, a. spikthrough the hole and engaging the wood.

13. A shear developer for a wood and concrete structure comprising atruncated isosceles triangular metal plate adapted to be seated in atrough in the wood with its truncated end embedded in the bottom of thetrough and most of its sides embedded in the sides of the trough and theremainder embedded in the concrete with a portion adjacent the baseextending beyond the mouth of the trough and provided with a hole in theextending portion, and a spike through the hole and seated in the bottomof the trough.

14. A shear developer for a wood and concrete structure comprising atruncated isosceles triangular metal plate adapted to be seated in atrough in the wood with its truncated end embedded in the bottom of thetrough and most of its sides embedded in the sides of the trough and theremainder embedded in the concrete with a portion adjacent the baseextending beyond the mouth of the trough and provided with a hole in theextending portion and portions at points embedded in the wood cut andpushed out to engage the wood, and a spike through the hole and seatedin the bottom of the trough.

JAMES F. SEILER.

